The overall objective of this K23 award proposal is to provide support for the additional training and experience necessary for the candidate, Junko Takeshita, MD, PhD, to transition from recent post-doctoral trainee and current Instructor in Dermatology to an independent patient-oriented investigator with a focus on health and healthcare disparities in psoriasis. Specifically, the aims of this proposal are to identify, defin, and understand disparities between African American and Caucasian Medicare beneficiaries in the treatment of psoriasis. We hypothesize that: 1) initiation of specific psoriasis therapies and persistence on therapies are different between African American and Caucasian patients with psoriasis, and 2) there are important differences in patient-level factors such as perceptions of psoriasis and attitudes towards treatments between the two racial groups that contribute to differential treatment of psoriasis. As clinicians are currently unaware of existing disparities in psoriasis treatment, we seek to shift current clinical practice paradigms with this proposal by newly identifying and establishing an understanding of racial disparities in the treatment of psoriasis with the goal of reducing any identified disparities and ultimately improving treatment and clinical outcomes, particularly among African American patients with psoriasis. A sequential mixed methods approach will be utilized to address the proposed aims: i) first, a quantitative longitudinal cohort study using Medicare data will be performed in order to compare initiation of therapies and persistence on therapies between African American and Caucasian Medicare beneficiaries with psoriasis; and ii) second, a qualitative study, informed by results from the quantitative study, will be performed using semi-structured interviews and freelists in order to identify patient- level determinants of the identified psoriasis treatment disparities between African Americans and Caucasians. In order to achieve these goals, the candidate will need training in three critical areas: 1) use of Medicare claims data; 2) disparities research methods; and 3) qualitative and mixed methods research. The candidate's training plan, which includes a combination of didactic coursework, practical experience through the completion of her proposed research, and directed mentorship from her expert mentoring team over the five year award period, will enable her to launch a successful career as an independent investigator in patient-oriented research and make important contributions to the field of dermatology via the study of disparities in the care of psoriasis.